In recent years, there have been researches on a technique to improve transmission efficiency of wireless communication and the like by carrying out multiplex communication utilizing orbital angular momentum (OAM) of an electromagnetic wave (for example, refer to Fabrizio Tamburini, et al., “Encoding many channels on the same frequency through radio vorticity: first experiment test”, New Journal of Physics 14 (2012) 033001 (17 pp), 1 Mar. 2012, and Edfors, Ove et al., “Is orbital angular momentum (OAM) based radio communication an unexploited area?”, IEEE Transactions on Antennas and Propagation, 2012, vol. 60:2, pp. 1126-1131). Since electromagnetic waves having different modes of orbital angular momentum (OAM) is possible to exist in the same space at the same time, it is considered that a plurality of electromagnetic waves having different modes of orbital angular momentum (OAM) are superimposed to be sent from a sending machine to a receiving machine. The receiving device carries out an opposite process corresponding to that on the sending side, thereby being capable of separating the received electromagnetic wave into electromagnetic waves corresponding to the individual orbital angular momentum (OAM).